East Michigan vegetable regional report – June 22, 2016

Harvest is picking up for fruiting vegetables. Summer meetings are coming up.


There are chances of rain tomorrow (June 23), Friday (June 24), Saturday and Sunday-Monday.

Here are rainfall (inches since April 1) and degree-day (base 50 degrees Fahrenheit since March 1) accumulations to date from Michigan State University Enviro-weather stations in the region.

Rainfall and degree-day (DD) totals as of June 22, 2016


DD (+ added from last week)

5-year average

Rainfall (+ added from last week)

5-year average


753 (+157)


6.59 (+0.35)



784 (+157)


3.48 (+0.83)



817 (+165)


4.40 (+0.95)



785 (+160)


4.65 (+1.17)



808 (+152)


5.96 (+0.94)



687 (+149)


5.76 (+1.26)



787 (+162)


5.49 (+1.09)



825 (+172)


4.77 (+0.19)



701 (+146)


7.97 (+2.16)



Some watermelons and melons that were under plastic tunnels are now vining and flowering, and summer squashes are just starting to show up at markets with some volume. Every plant I’ve seen looks like it is loaded for heavy picking over the next few weeks. Winter squash and pumpkins are being seeded. Transplanted acorn squash is getting tall but not yet flowering in some places.

Squash vine borer could start showing up across the region this week. The Michigan State University Enviro-weather squash vine borer prediction model has predicted emergence of the first generation of moths where more than 800 growing degree-days (GDD) base 50 has accumulated (see table), and egglaying should start about a week after of that. Management options are covered in the MSU Extension article, “Squash vine borer biology and management.” Organic options are limited, but Entrust is one that has had some successful suppression in Ohio.

Some field tomatoes that were under fabric tunnels are now flowering. Greenhouse tomatoes are being continually picked in Amish country. Early blight has just started in some greenhouses, and I’ve heard reports of gray mold.

Pickling cucumbers are continually being seeded. Fresh market cucumbers are on their first to third picking. There have been spotty outbreaks of bacterial-looking symptoms in some fresh market plantings. MSU Extension recommends getting a copper application on before the upcoming rain if possible. Any splashing will spread it around. We are also closing in on the time when downy mildew can show up. It is a good idea to begin protectant sprays with Bravo or Mancozeb after this week’s rains.

5 cucumber leaves with tan splotches and lesions.

Yellow halos surrounding dark, water-soaked lesions that become light-colored and brittle are fairly consistent symptoms of bacterial disease such as bacterial leaf spot (Xanthomonas) and angular leaf spot (Pseudomonas). Copper is recommended for treatment when symptoms arise, especially before a rain that may splash it around to other plants. Photo: Ben Phillips, MSU Extension.

Onions are due for the first of two applications of Movento for thrips control. Thrips have been higher than usual for this time of year because it has been relatively dry. If rain is in the forecast, Movento should be applied with a non-ionic surfactant and with enough time to dry before rain.

Strawberry harvest is still in full swing in some places, while others are being renovated this week.

Special upcoming events

The MSU Weed Tour is being held June 29 at the Plant Pathology Field Lab on south campus, 3735 N College Road, Lansing MI 48910. It is an all-day tour starting at 8:30 a.m. Registration is $25 ahead of time or $35 on site.

On July 13 from 6–9 p.m., commercial vegetable growers are invited with their families to join MSU Extension vegetable specialists at the new Helena Chemical facility north of Imlay City, Michigan, for a mid-summer vegetable clinic, social dinner and a tour of the new facility. Please RSVP with the number of eaters to Angelique Rooney at 989-758-2500 by July 6. The dinner is fully sponsored by Helena Chemical and Farm Bureau Insurance, and RUP credits have been requested from the Michigan Department of Agriculture and Rural Development.

Please contact me at .(JavaScript must be enabled to view this email address) or 616-901-7513 to grab any suspected disease samples from your farm, or send the diseased plant parts to MSU Diagnostic Services.

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